Sorting a Staphylococcus aureus phage display library against ex vivo biomaterial

Area of Science:

• Microbiology
• Biotechnology
• Infectious Diseases

Background:

• Central venous catheters (CVCs) are crucial medical devices but are prone to microbial colonization and biofilm formation.
• Understanding the host proteins that interact with CVC surfaces is essential for developing strategies to prevent catheter-related complications.

Purpose of the Study:

• To identify Staphylococcus aureus-derived proteins that bind to central venous catheters (CVCs).
• To investigate the presence of specific host proteins, such as fibrinogen and beta2-glycoprotein I, adsorbed onto CVC surfaces.

Main Methods:

• Construction and screening of a phage display library derived from Staphylococcus aureus DNA.
• Panning the library against explanted CVCs to isolate binding phage clones.
• Characterization of phage clones by sequencing to identify encoded proteins.
• Detection of adsorbed proteins on CVCs using specific antibodies.

Main Results:

• After initial panning, approximately 50% of phage clones encoded proteins interacting with mammalian proteins.
• Subsequent panning rounds led to a dominance of fibrinogen-binding and beta2-glycoprotein I (beta2-GPI)-binding phage particles.
• Fibrinogen was the most abundant protein detected on tested CVCs.
• Beta2-glycoprotein I was also detected on all tested CVCs.

Conclusions:

• Phage display is effective in identifying Staphylococcus aureus proteins that bind to CVC surfaces.
• Fibrinogen and beta2-GPI are significant host proteins adsorbed onto CVCs, potentially influencing microbial adhesion and biofilm formation.
• These findings may offer insights into novel therapeutic or preventative strategies against CVC-associated infections.